1. Field of the Invention
The present invention relates to data security and more particularly to e-mail message security.
2. Description of the Related Art
Information technologists view network security to be a top priority in the deployment and management of information technology resources. While network security often involves such diverse aspects of the enterprise that range from routing gateways onto the public network to virus detection and remediation, securing the privacy and confidentiality of data remains a bedrock mission for the network security specialist. Generally, data security relates directly to the science of cryptography as applied to data of interest.
In cryptography, security can be achieved through encryption. Encryption involves the conversion of a clear-text message into a data stream that appears to be a meaningless and random sequence of bits known as cipher text. A cryptographic algorithm, also known as cipher, is the mathematical function that processes plain text input to produce a cipher text message. All modern ciphers use keys together with plain text as the input to produce cipher text. In this regard, a key is a value that works with a cryptographic algorithm to produce specific cipher text. The same or a different key can be supplied to the decryption function to recover plain text from cipher text.
There are a number of techniques used to encrypt and decrypt information with passwords. Generally, encryption and decryption approaches can be classified as symmetric and asymmetric in nature. The most common approach for symmetric encryption involves the one-way hashing of a known password. A pass-phrase hash is a method of transforming a text string that can be remembered by a human user, into a result that can be used either as an “authenticator”, which can be stored and used at a later time to check whether a user knows the pass-phrase, and as pseudorandom data for a cipher or secret key.
Securing the confidentiality of a message using encryption can be effective as between parties to a confidential exchange of information. However, in certain circumstances, the nature of a message may require context not evident from message content itself. Rather, a real-time conversation will be required to provide the context. In other circumstance, it may be advantageous to avoid complete delivery until auxiliary circumstances can be met such as the agreement of the recipient of the message to abide by terms proposed by the sender of the message.